The latest qBittorrent 3.3.5 ships with useful new feature: torrent management mode. If you set this mode to automatic and you change the category or save path, the torrent is relocated to the new category folder / new save path:

Other changes in qBittorrent 3.3.5 include:

sort labels with natural sort algorithm in the right-click menu;

add option to automatically remove .torrent files upon adding;

display notifications when a torrent is added;

new cookies management dialog and various related fixes;

use unique temp directories;

add option to bind directly to an IP instead of using a network Interface;

add detailed tooltips on the progress and availability bars in the General button of each torrent;

Download qBittorrent

Download qBittorrent (binaries available for Windows, Mac and multiple Linux distributions as well as source)

qBittorrent is available in the official Ubuntu repositories, but it's an old version. Ubuntu 16.04 provides version 3.3.1, Ubuntu 15.10 has qBittorrent 3.2.3, while Ubuntu 16.04 (and thus, Linux Mint 17.x) still uses the old qBittorrent 3.1.8.

If you don't care about using the latest version, you can install it from the repositories by searching for it in Ubuntu Software, Synaptic, or by using the following command:

sudo apt install qbittorrent

To install the latest qBittorrent 3.3.5 in Ubuntu 16.04, 15.10 or 14.04 / Linux Mint 18 or 17.x and derivatives, you can use the official qBittorrent PPA. Add the PPA and install the application using the following commands: